16.07.2021 17:41, Rob Herring пишет:
> On Fri, Jul 2, 2021 at 8:05 AM Dmitry Osipenko <digetx@xxxxxxxxx> wrote:
>>
>> 23.04.2021 19:32, Thierry Reding пишет:
>>> +void of_iommu_get_resv_regions(struct device *dev, struct list_head *list)
>>> +{
>>> + struct of_phandle_iterator it;
>>> + int err;
>>> +
>>> + of_for_each_phandle(&it, err, dev->of_node, "memory-region", "#memory-region-cells", 0) {
>>> + struct iommu_resv_region *region;
>>> + struct of_phandle_args args;
>>> + struct resource res;
>>> +
>>> + args.args_count = of_phandle_iterator_args(&it, args.args, MAX_PHANDLE_ARGS);
>>> +
>>> + err = of_address_to_resource(it.node, 0, &res);
>>> + if (err < 0) {
>>> + dev_err(dev, "failed to parse memory region %pOF: %d\n",
>>> + it.node, err);
>>> + continue;
>>> + }
>>> +
>>> + if (args.args_count > 0) {
>>> + /*
>>> + * Active memory regions are expected to be accessed by hardware during
>>> + * boot and must therefore have an identity mapping created prior to the
>>> + * driver taking control of the hardware. This ensures that non-quiescent
>>> + * hardware doesn't cause IOMMU faults during boot.
>>> + */
>>> + if (args.args[0] & MEMORY_REGION_IDENTITY_MAPPING) {
>>> + region = iommu_alloc_resv_region(res.start, resource_size(&res),
>>> + IOMMU_READ | IOMMU_WRITE,
>>> + IOMMU_RESV_DIRECT_RELAXABLE);
>>> + if (!region)
>>> + continue;
>>> +
>>> + list_add_tail(®ion->list, list);
>>> + }
>>> + }
>>> + }
>>> +}
>>> +EXPORT_SYMBOL(of_iommu_get_resv_regions);
>>
>> Any reason why this is not EXPORT_SYMBOL_GPL? I'm curious what is the
>> logic behind the OF symbols in general since it looks like half of them
>> are GPL.
>
> Generally, new ones are _GPL. Old ones probably predate _GPL.
>
> This one is up to the IOMMU maintainers.
Thank you.
